Input device, input method, and computer program for inputting characters, numbers, or symbols by using an on-screen keyboard

ABSTRACT

An input control unit includes: a keyboard display unit configured to display a keyboard that shows a set of a plurality of characters or symbols that can be input on a screen and receive a user&#39;s selection of a character or a symbol so as to enter the character or the symbol received from the user on a mobile terminal; an input receiving unit configured to receive the character or the symbol selected by the user from among the plurality of characters or symbols; and a screen control unit configured to change a priority of displaying the keyboard screen if an operation is received from a rear touch panel provided on the rear face of a mobile terminal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to technology for enteringcharacters, numbers, or symbols, and more particularly, to an inputdevice and an input method for entering characters, numbers, or symbolsby using an on-screen keyboard.

2. Description of the Related Art

A keyboard is generally used to input characters or symbols in devices,such as personal computers, word processors, or the like. However, in amobile terminal (e.g., a portable type game device, a mobile phone, orthe like), or in a household electrical appliance (e.g., a printer, arefrigerator, or the like), user has to input characters or symbols byusing limited number of buttons, switches, or the like. Therefore, avariety of types of contrivance is required in order to improve userfriendliness.

As an example of such contrivance, in a device where a display device(e.g., a liquid crystal panel or the like) is provided, a so-calledon-screen keyboard is used, wherein a keyboard image is displayed on adisplay device and each key of the keyboard being displayed can beselected by a pointing device or the like. Particularly, in a devicethat provides a touch panel, a user can enter characters or symbols bytouching respective keys of a keyboard being displayed. Therefore,similar operability with that of using a keyboard can be provided.

SUMMARY OF THE INVENTION

Although an on-screen keyboard contributes to the improvement of userfriendliness in this manner, there are a lot of occasions to entercharacters or symbols by using a mobile terminal or the like nowadays.Therefore, a user interface that realizes a more convenient input methodis strongly required.

The present invention addresses the aforementioned issue, and a purposethereof is to provide an input technology with high user friendliness.

According to an embodiment of the present invention, an input device isprovided. The input device includes: a display unit configured todisplay a keyboard screen that shows a set of a plurality of charactersor symbols that can be input on a screen and receive a user's selectionof a character or a symbol so as to enter the character or the symbolreceived from the user on a mobile terminal; an input receiving unitconfigured to receive the character or the symbol selected by the userfrom among the plurality of characters or symbols; and a screen controlunit configured to change a display priority of displaying the keyboardscreen if an operation is received from a touch panel provided on therear face of the mobile terminal.

Optional combinations of the aforementioned constituting elements, andimplementations of the invention in the form of methods, apparatuses,systems, or the like may also be practiced as additional modes of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the accompanying drawings that are meant to be exemplary,not limiting, and wherein like elements are numbered alike in severalfigures, in which:

FIG. 1 shows an external view of a mobile terminal according to anexemplary embodiment;

FIG. 2 shows an external view of the mobile terminal according to theexemplary embodiment;

FIG. 3 shows the configuration of the mobile terminal;

FIG. 4 shows an exemplary screen wherein an on-screen keyboard isdisplayed;

FIG. 5 shows an exemplary screen wherein an on-screen keyboard isdisplayed;

FIG. 6 shows an image for illustrating a function for scrollingconversion candidate character strings being displayed;

FIG. 7 shows an image for illustrating a function for scrollingconversion candidate character strings being displayed;

FIG. 8 shows an image for illustrating a function for scrollingconversion candidate character strings being displayed;

FIG. 9 shows an image for illustrating a function for scrollingconversion candidate character strings being displayed;

FIG. 10 shows an image for illustrating a function for scrollingconversion candidate character strings being displayed;

FIG. 11 shows an image for illustrating a function for scrollingconversion candidate character strings being displayed;

FIG. 12 shows a flowchart indicating a procedure for scrollingconversion candidate character strings;

FIG. 13 shows an image for illustrating a function for switchingkeyboards;

FIG. 14 shows an image for illustrating a function for switchingkeyboards;

FIG. 15 shows an image for illustrating a function for switchingkeyboards;

FIG. 16 shows an image for illustrating a function for switchingkeyboards;

FIG. 17 shows a flowchart indicating a procedure for switchingkeyboards;

FIG. 18 shows an image for illustrating an input control function forsymbols used as a pair;

FIG. 19 shows an image for illustrating an input control function forsymbols used as a pair;

FIG. 20 shows examples of symbols used as a pair;

FIG. 21 shows a flowchart indicating a procedure of an input controlmethod for symbols used as a pair;

FIG. 22 shows an image for illustrating a display control function foran on-screen keyboard screen and an application screen;

FIG. 23 shows an image for illustrating a display control function foran on-screen keyboard screen and an application screen; and

FIG. 24 shows a flowchart indicating a procedure of a display controlfunction for an on-screen keyboard screen and an application screen.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be described by reference to the preferredembodiments. This does not intend to limit the scope of the presentinvention, but to exemplify the invention.

FIGS. 1 and 2 show an external view of a mobile terminal 10 according toan exemplary embodiment. As shown in FIG. 1, on the front face of themobile terminal 10 (i.e., the surface facing a user when the user holdsand manipulates the mobile terminal 10), buttons 20 such as aninstruction input button 21, directional keys 22, an R button 23, an Lbutton 24, or the like, and a display device 68 are provided. With thedisplay device 68, a touch panel 69 for detecting contact made by afinger of a user, a stylus pen, or the like is provided.

As shown in FIG. 2, on the rear face of the mobile terminal 10, a reartouch panel 70 is provided. Although a display device may be providedalso on the rear face of the mobile terminal 10 in a similar manner withthat of the front face, a display device is not provided on the rearface of the mobile terminal 10 and only the rear touch panel 70 isprovided on the rear face according to the exemplary embodiment.

A user can, for example, manipulate the instruction input button 21 withhis/her right hand thumb, manipulate the direction keys 22 with his/herleft hand thumb, manipulate the R button 23 with his/her right handindex finger or middle finger, manipulate the L button 24 with his/herleft hand index finger or middle finger, manipulate the touch panel 69with his/her thumbs of both hands, and manipulate the rear touch panel70 with his/her ring fingers or pinky fingers of both hands whileholding the mobile terminal 10 with his/her both hands. In case of usinga stylus pen or the like the user can manipulate the touch panel 69 andthe instruction input button 21 for example with the right hand by usingthe stylus pen or by the index finger, manipulate the directional keys22 with the left hand thumb, manipulate the L button 24 with the lefthand index finger or middle finger, and manipulate the rear touch panel70 with the left hand ring finger or the pinky finger while holding themobile terminal 10 with the left hand.

FIG. 3 shows the configuration of the mobile terminal 10. The mobileterminal 10 comprises the buttons 20, the touch panel 69, the rear touchpanel 70, a control unit 40, a keyboard storage unit 60, a dictionarydata storage unit 62, and a display device 68. Those elements areimplemented by a CPU of a computer, memory, a program loaded into thememory, or the like in terms of hardware components. FIG. 3 depictsfunctional blocks implemented by cooperation of these components.Therefore, it will be obvious to those skilled in the art that thefunctional blocks may be implemented in a variety of ways, by hardwareonly, software only, or a combination thereof.

The keyboard storage unit 60 retains screen data of an on-screenkeyboard where a plurality of keys (e.g., character keys, number keys,symbol keys, or the like) that can be input by a user are arranged.According to the exemplary embodiment, the keyboard storage unit 60retains screen data of a plurality of on-screen keyboards correspondingto a plurality of types of character set or symbol set so as to allow auser to input character strings in a plurality of languages. Thedictionary data storage unit 62 retains dictionary data. If a Japaneseword is input phonetically, the dictionary data is used in order toconvert the input character string of the Japanese word into Kanji. If apart of an English word is input, the dictionary data is used in orderto extract and display a complete word expected to be input.

The control unit 40 receives an operation input by a user via thebuttons 20, the touch panel 69, and the rear touch panel 70. Based onthe input operation received from the user, the control unit 40 executesan application 42 such as a game program or the like, executes an inputfunction for entering characters or symbols into the application 42 orthe like, or executes other various functions. The control unit 40includes the application 42 and the input control unit 80. The inputcontrol unit 80 includes an input receiving unit 81, a keyboard displayunit 82, an output unit 83, an input character string acquiring unit 84,a conversion candidate acquiring unit 85, a conversion candidate displayunit 86, a switching control unit 87, and a screen control unit 88.

The keyboard display unit 82 reads a screen of an on-screen keyboardfrom the keyboard storage unit 60 and displays the on-screen keyboard onthe display device 68. Based on an instruction input by a user throughthe button 20, the touch panel 69, or the rear touch panel 70, the inputreceiving unit 81 determines which of the keys on the on-screen keyboardis entered and receives user's selection of a character, a number, or asymbol.

The input character string acquiring unit 84 acquires the characterselected by the user and received by the input receiving unit 81 andadds the character to an input character string. The conversioncandidate acquiring unit 85 acquires one or more conversion candidatecharacter strings, which is a conversion of a character string includingthe input character string. The conversion candidate acquiring unit 85may acquire one or more conversion candidate character strings when theconversion candidate acquiring unit 85 receives from a user aninstruction to request the display of conversion candidate characterstrings, which are conversions of the input character string.Alternatively, the conversion candidate acquiring unit 85 may acquireconversion candidate character strings, which are conversions of theinput character string, when an addition is made to the input characterstring. The conversion candidate acquiring unit 85 may acquire expectedconversion candidate character strings, which are extracted fromconversion candidate character strings that are conversions of characterstrings including the input character string in the beginning thereof byassuming following input character strings. The conversion candidateacquiring unit 85 may generate conversion candidate character strings byreferring the dictionary data storage unit 62, or may notify anotherdevice or application of the input character string so as to acquireconversion candidate character strings converted by the device or theapplication. The conversion candidate acquiring unit 85 may utilize anyknown technology as a conversion function or as a predictive conversionfunction. In case of acquiring a plurality of conversion candidatecharacter strings, the conversion candidate acquiring unit 85 alsoacquires the order of displaying the strings.

The conversion candidate display unit 86 displays the conversioncandidate character strings acquired by the conversion candidateacquiring unit 85 in the order of displaying on the display device 68.If a user determines one conversion candidate character string among theconversion candidate character strings displayed by the conversioncandidate display unit 86 by touching one of the conversion candidatecharacter strings, by selecting or pressing a determination key or thelike for fixing a conversion candidate character string being selected,the input receiving unit 81 receives the determination and the outputunit 83 outputs the determined conversion candidate character string tothe application 42 or the like. For a character string that does notrequire conversion, such as an alphanumeric character string or a symbolstring, the output unit 83 may output the string directly withoutconversion. For example, in case an on-screen keyboard for enteringJapanese is selected, an output may be made via the conversion functioneven if an alphanumeric character string or a symbol string is input,and in case an on-screen keyboard for entering English is selected, anoutput may be made directly without the conversion function. Even incase an on-screen keyboard for entering English is selected, apredictive conversion function as described above may be used forEnglish words. The details on aforementioned basic technologies for anon-screen keyboard will not be given here since any known technology canbe used.

The switching control unit 87 switches on-screen keyboards utilized by auser among a plurality of on-screen keyboards stored in the keyboardstorage unit 60. The screen control unit 88 controls a display status ofa screen displayed by the application 42 and an on-screen keyboardscreen. The detail on these functions will be described later.

FIG. 4 shows an exemplary screen wherein an on-screen keyboard isdisplayed. If a text box 102, which is for entering a search keyword andwhich the application 42 has displayed on a screen, is activated, theapplication 42 displays a caret 104 indicating an input position in thetext box 102 and activates the input control unit 80 in order to receivean input character string. The keyboard display unit 82 reads a screenof a predetermined type of an on-screen keyboard from the keyboardstorage unit 60 and displays the on-screen keyboard. In FIG. 4, anon-screen keyboard 106 for entering Japanese is displayed.

The on-screen keyboard 106 for entering Japanese includes a sub screenfor entering symbols or numbers in addition to a basic screen forentering Japanese characters. If the button 108 for switching to a subscreen is entered on the on-screen keyboard 106, the keyboard displayunit 82 reads a sub screen 112 of an on-screen keyboard for enteringJapanese from the keyboard storage unit 60 and displays the sub screen112 on the display device 68 as shown in FIG. 5. If a button 114 forswitching to a basic screen is entered on the sub screen 112, thekeyboard display unit 82 displays the basic screen shown in FIG. 4again.

(Scrolling Conversion Candidate Character Strings)

FIGS. 6 to 11 show images for illustrating a function for scrollingconversion candidate character strings being displayed. The conversioncandidate display unit 86 displays the conversion candidate characterstrings, which are acquired by the conversion candidate acquiring unit85, in the order of displaying in the conversion candidate display row120 as shown in FIG. 6. The conversion candidate display unit 86displays a conversion candidate character string having the highestpriority of the displaying order at the left end of the conversioncandidate display row 120, and displays following conversion candidatecharacter strings in the order of displaying from left to right,subsequently. In FIG. 6, character strings, such as, “Aoyama icchoume(in a combination of Kanji), “Aoyama icchoume (in another combination ofKanji), etc. are displayed in sequence as conversion candidate characterstrings of “Aoyama icchoume (in Hiragana)” in the conversion candidatedisplay row 120. In case that there are too many conversion candidatecharacter strings to display and the conversion candidate characterstrings do not fit within the conversion candidate display row 120, theconversion candidate display unit 86 displays a portion of theconversion candidate character strings that can be displayed in theconversion candidate display row 120, and concurrently displays a listdisplay button 122 for displaying conversion candidate character stringsas a list. Upon receiving an input for the list display button 122, theconversion candidate display unit 86 broadens the display region forconversion candidate character strings and displays the conversioncandidate character strings as a list.

As shown in FIG. 7, in case that all of the conversion candidatecharacter strings can not be displayed in the conversion candidatedisplay row 120, the conversion candidate display unit 86 causes theconversion candidate character strings to scroll in the conversioncandidate display row 120 upon receiving a flick operation on theconversion candidate display row 120. In FIG. 7, since a user slideshis/her finger to the left, the conversion candidate display unit 86causes the conversion candidate character strings to scroll to the left.Consequently, conversion candidate character strings of a lower priorityin the displaying order, which have not been displayed in the conversioncandidate display row 120, can be scrolled and displayed sequentially.The conversion candidate display unit 86 causes the conversion candidatecharacter strings to scroll cyclically by displaying the firstconversion candidate character string, which is the first in thedisplaying order, subsequent to the last conversion candidate characterstring, which is the last in the displaying order. Consequently, if auser wants to move back to a conversion candidate character string of ahigher priority in the displaying order after scrolling conversioncandidate character strings in the displaying order, the user canreadily move back to the first conversion candidate character string inthe displaying order by keeping scrolling in the forward directioninstead of moving back by scrolling in the opposite direction.Therefore, user friendliness can be improved.

In FIG. 8, since a user slides his/her finger to right, the conversioncandidate character strings are scrolled to the right. In this process,upon receiving a flick operation to scroll the conversion candidatecharacter strings in the direction opposite from that of the displayingorder while the first conversion candidate character in the displayingorder is displayed, the conversion candidate display unit 86 causes theconversion candidate character strings to scroll in the oppositedirection, starting from the last conversion candidate character stringin the displaying order. That is, when scrolling conversion candidatecharacter strings to the right, the last conversion candidate characterstring in the displaying order is displayed subsequent to the firstconversion candidate character string in the displaying order.Consequently, by performing a flick operation in the right direction onthe first display screen shown in FIG. 6, conversion candidate characterstrings of lower priority can be readily displayed from the lastconversion candidate character string in the displaying order.Therefore, user friendliness can be improved.

While scrolling the conversion candidate character strings in theopposite direction, before displaying the last conversion candidatecharacter string in the displaying order subsequent to the firstconversion candidate character string in the displaying order, theconversion candidate display unit 86: once stops scrolling; or oncestops scrolling and then scrolls a predetermined amount back in theforward direction, and then scrolls the strings in the oppositedirection again. In a similar manner, while scrolling the conversioncandidate character strings in the forward direction, before displayingthe first conversion candidate character string in the displaying ordersubsequent to the last conversion candidate character string in thedisplaying order, the conversion candidate display unit 86 may: oncestop scrolling; or once stop scrolling and then scroll a predeterminedamount back in the opposite direction, and may scroll the strings in theforward direction again. This enables the conversion candidate characterstrings to scroll cyclically by connecting the first conversioncandidate character string in the displaying order and the lastconversion candidate character string in the displaying order, andconcurrently allows a user to recognize the border between them.

According to the exemplary embodiment, conversion candidate characterstrings are classified into three groups and the displaying order isfirst determined among the groups. The three groups are: a group ofcharacter strings including Kanji, a group of character stringsincluding only Japanese Kana (i.e., Japanese Hiragana and/or JapaneseKatakana), a group of character strings including Japanese Romaji (i.e.,Japanese written in Roman characters). For example, the displaying ordermay be defined as the order: the group of character strings includingKanji; the group of character strings including only Kana; and the groupof character strings including Romaji. In each of the groups, thedisplaying order of conversion candidate character strings is furtherdetermined. For example, in case that a user wants to search for aconversion candidate character string belonging to a group of a higherpriority in the displaying order (e.g., a character string includingKanji), the user just has to scroll the conversion candidate characterstrings in the conversion candidate display row to the left so that theconversion candidate character strings are displayed subsequentlystarting from the first conversion candidate character string in thedisplaying order to that of a lower priority. Alternatively, in casethat a user wants to search for a conversion candidate character stringbelonging to a group of a lower priority in the displaying order (e.g.,a character string in Romaji, or a character string only includingKana), the user just has to scroll the conversion candidate characterstrings in the conversion candidate display row to the right so that theconversion candidate character strings are displayed subsequentlystarting from the last conversion candidate character string in thedisplaying order to that of a higher priority. This improves userfriendliness.

Although an explanation has been given on a case where a characterstring in Japanese is input regarding FIGS. 6 to 9, a similarexplanation applies to a case where a character string in English isinput as shown in FIG. 10. As described above, if the input characterstring acquiring unit 84 acquires an input character string in Romanalphabet, the conversion candidate acquiring unit 85 acquires expectedconversion candidate character strings including the input characterstring or including a character string similar to the input characterstring, and the conversion candidate display unit 86 displays aplurality of expected conversion candidate character strings having beenacquired in the conversion candidate display row 120. In the exampleshown in FIG. 10, character strings, such as, “japan,” “japanese.uk,”“Japanese,” etc. are displayed in the conversion candidate display row120 as a conversion candidate character string of “japan,” which is theinput character string. If a user performs a flick operation in theright or in the left direction in the conversion candidate display row120, the conversion candidate display unit 86 scrolls the conversioncandidate character strings to the right or to the left and displaysconversion candidate character strings which have not been displayedsequentially.

Although an explanation has been given on a case where a characterstring is input by using a horizontally long keyboard in FIGS. 6 to 10,a keyboard 139 similar to a keypad on a mobile phone may be used asshown in FIG. 11. In this case, the conversion candidate display unit 86may display a plurality of expected conversion candidate characterstrings in a vertical layout in the conversion candidate display column124 as shown in FIG. 11. Upon receiving a flick operation upwards ordownwards in the conversion candidate display column 124, the conversioncandidate display unit 86 scrolls the conversion candidate characterstrings upwards or downwards and displays conversion candidate characterstrings which have not been displayed sequentially.

FIG. 12 shows a flowchart indicating a procedure for scrollingconversion candidate character strings. If the conversion candidateacquiring unit 85 acquires one or more conversion candidate characterstrings, the conversion candidate display unit 86 displays theconversion candidate character strings in the conversion candidatedisplay region (S100). In case that all of the conversion candidatecharacter strings are displayed in the conversion candidate displayregion (N in S102), the conversion candidate display unit 86 skips thefollowing steps. In case that the conversion candidate character stringsdo not fit within the conversion candidate display region and allconversion candidate character strings can not be displayed in theconversion candidate display region (Y in S102), upon receiving a flickoperation on the conversion candidate display region (Y in S104), theconversion candidate display unit 86 causes the conversion candidatecharacter strings to scroll (S106). In this process, in case of passingthe border between the first conversion candidate character string inthe displaying order and the last conversion candidate character stringin the displaying order (Y in S108), the scrolling is stopped for apredetermined time period (S110) and the procedure returns to step S104.In case that no flick operation is received in the conversion candidatedisplay region in step S104 (N in S104), or in case of not passing theborder between the first conversion candidate character string in thedisplaying order and the last conversion candidate character string inthe displaying order in step S108 (N in S108), the procedure returns tostep S104.

(Switch Control of Keyboards)

FIGS. 13 to 16 show images for illustrating a function for switchingkeyboards. In the screen shown in FIG. 4, upon receiving an input forthe keyboard switching button 110, the switching control unit 87 causesa transition to a switching mode for switching on-screen keyboards,reads a keyboard image 130, which is a scaled down on-screen keyboard106 being displayed, from the keyboard storage unit 60 and displays thekeyboard image 130 as shown in FIG. 13. Since the keyboard image 130 issmaller than the on-screen keyboard 106, if the keyboard image 130 isdisplayed in the center in the horizontal direction, available spacesemerge on the right and left of the keyboard image 130. The switchingcontrol unit 87 reads one or more keyboard images that are scaled-downimages of other on-screen keyboards available for switching from thekeyboard storage unit 60 and displays the keyboard images in accordancewith a displaying order thereof. For example, the switching control unit87 displays a keyboard image 132 subsequent in the displaying order onthe right and displays a keyboard image 134 preceding in the displayorder on the left, respectively.

Upon receiving a flick operation on the region where the keyboard imagesare displayed, the switching control unit 87 scrolls a plurality ofkeyboard images to the right or to the left as shown in FIG. 14. In FIG.14, since a user slides his/her finger to the left, the switchingcontrol unit 87 causes the keyboard images to scroll to the left. Asshown in FIG. 15, the switching control unit 87 stops the scrolling in astate where one of the keyboard images is displayed in the center in thehorizontal direction. In FIG. 15, the keyboard image 132 of an on-screenkeyboard for entering English alphabet is displayed in the center. Inthis process, if a user inputs the button 136 for accepting a keyboardthat is displayed in the center and selected as a candidate, theswitching control unit 87 terminates the switching mode and reads anon-screen keyboard 138 that corresponds to the keyboard image 132 thathas been selected as a candidate from the keyboard storage unit 60 anddisplays the on-screen keyboard 138 as shown in FIG. 16. Consequently,even in case that a plurality of on-screen keyboards are provided, auser can readily switch and use the keyboards, which improves userfriendliness.

Upon receiving a tap operation on one of the keyboard images, theswitching control unit 87 may switch a keyboard to the on-screenkeyboard corresponding to the tapped keyboard image. For example, uponreceiving a tap operation on the keyboard image 132 that is displayed onthe right in the state shown in FIG. 13, the switching control unit 87may switch an on-screen keyboard to the on-screen keyboard 138 forinputting English corresponding to the keyboard image 132 as shown inFIG. 16. Consequently, as a user can readily switch an on-screenkeyboard to another on-screen keyboard without scrolling keyboardimages, user friendliness can be improved.

According to the exemplary embodiment, each on-screen keyboard includesa basic screen for inputting characters and a sub screen for inputtingsymbols or numbers as described above. However, a user has difficulty indetermining which type of on-screen keyboard is shown even if the userviews a keyboard image of a sub screen since a sub screen image issubstantially same as that of another on-screen keyboard regardless ofthe type of on-screen keyboards. Therefore, the switching control unit87 does not accept an input instruction to switch keyboard screens whena sub screen is displayed and allows the transition to the switchingmode only when a basic screen is displayed.

If the switching control unit 87 causes a transition to the switchingmode, the screen of an on-screen keyboard is switched to a keyboardimage of a scaled-down on-screen keyboard, and parts of other keyboardimages are displayed on the left and on the right. This allows a user tounderstand intuitively that he/she can switch on-screen keyboards byscrolling the keyboard images. The switching control unit 87 may adopt avisual expression where an on-screen keyboard appears as if it is oncepressed down when making transition to a switching mode. In this case,an instruction to be input in order to make transition to a switchingmode may be an operation looking as if pressing down an on-screenkeyboard, for example the operation may be a press-and-hold operation ata predetermined position on the on-screen keyboard. Conversely, theswitching control unit 87 may adopt a visual expression where anon-screen keyboard appears as if it once floats when making transitionto a switching mode. In this case, an instruction to be input in orderto make transition to a switching mode may be an operation looking as ifcausing the on-screen keyboard to float, for example the operation maybe a tap or a press-and-hold at a predetermined position on the reartouch panel 70.

FIG. 17 shows a flowchart indicating a procedure for switchingkeyboards. Upon receiving an operation for switching on-screen keyboardsfrom a user (Y in S200) when the keyboard display unit 82 displays anon-screen keyboard and the device is standing by for user input, theswitching control unit 87 displays a plurality of reduced keyboardimages side by side (S204) if a basic screen is being displayed (Y inS202). Upon receiving a flick operation on the region where the keyboardimages are displayed (Y in S206), the switching control unit 87 scrollsa plurality of keyboard images to the right or to the left so as toswitch candidates for selection (S208). Upon receiving an operation forfixing a candidate for selection from a user (Y in S210), the switchingcontrol unit 87 switches an on-screen keyboard to the determinedon-screen keyboard (S212). If an operation for switching on-screenkeyboards are not received (N in S200), or if a basic screen is notbeing displayed (N in S202), the following steps will be skipped. If aflick operation is not received in step S206 (N in S206), or anoperation for fixing a candidate for selection is not received in stepS210 (N in S210), the procedure returns to step S204.

(Input Control for Symbols Used as a Pair)

FIGS. 18 and 19 show images for illustrating an input control functionfor symbols used as a pair. The input character string acquiring unit 84stores in advance a start symbol and an end symbol that should be inputas a pair (e.g., parenthesis symbols, quotation marks, interrogationmarks, exclamation marks, or the likes). If a start symbol included inthe symbols or character strings stored in advance is input while thesub screen 112 for inputting symbols is displayed as shown in FIG. 18,the input character string acquiring unit 84 acquires not only the startsymbol but also the end symbol that is coupled to the start symbol as aninput character string. Further, the input character string acquiringunit 84 moves a caret 104 indicating an input position to a positionbetween the start symbol “(” and the end symbol “)” as shown in FIG. 19.This frees a user from the trouble of inputting an end symbol. Inaddition, following to the input of the start symbol, the user caneasily input a character string, which should be input between the startsymbol and the end symbol, between the start symbol and the end symbol.Therefore, user friendliness can be improved.

FIG. 20 shows examples of a symbol or the like used as a pair. The inputcharacter string acquiring unit 84 stores for example combinations ofsymbols shown in FIG. 20 as a combination of a start symbol and an endsymbol that should be input as a pair. The input character stringacquiring unit 84 may not only store single symbols, but may also storesymbols of which the start symbol or the end symbol is a combination oftwo or more symbols, numbers, or characters, such as, a block commentsymbol (e.g., “!——” and “——,” “/*” and “*/,” or the like), a start tagand an end tag in a Markup language, an opening and a closing for aletter, etc.

An input character string that is acquired by the input character stringacquiring unit 84 and includes a start symbol and an end symbol may beoutput directly from the output unit 83, or may be passed to theconversion candidate acquiring unit 85 as an unfixed character string.In the former case, if an application, an OS or the like of the outputdestination control the position of a caret, the input character stringacquiring unit 84 may instructs the output destination to move theposition of the caret to a position between a start symbol and an endsymbol.

This function can be applied not only to an on-screen keyboard but alsoto any input device for inputting symbols or the like.

FIG. 21 shows a flowchart indicating a procedure of an input controlmethod for symbols used as a pair. If a start symbol is entered (Y inS300), while the keyboard display unit 82 is displaying an on-screenkeyboard and the device is standing by for user input, the inputcharacter string acquiring unit 84 acquires the start symbol and the endsymbol as an input character string (S302), and moves a caret indicatingan input position to a position between the start symbol and the endsymbol (S304). If a start symbol is not input (N in S300), the followingsteps will be skipped.

(Display Control for an on-Screen Keyboard Screen and an ApplicationScreen)

FIGS. 22 and 23 show images for illustrating a display control functionfor an on-screen keyboard screen and an application screen. As shown inFIG. 22, if it is required to input characters, symbols, numbers, or thelike while the application 42 is running, the keyboard display unit 82displays the on-screen keyboard 106 so that the on-screen keyboard 106is superimposed on the screen 140 of the application. Upon receiving anoperation input from the rear touch panel 70 while the on-screenkeyboard 106 is being displayed, the screen control unit 88 lowers thepriority of displaying the on-screen keyboard 106, which has beendisplayed on the screen 140, to a level lower than that of the screen140 of the application. For example, the on-screen keyboard 106 may bedisplayed under the screen 140 of the application as shown in FIG. 23.Alternatively, the transparency factor of the on-screen keyboard 106 maybe raised so that the screen 140 displayed under the transparenton-screen keyboard 106 can be seen through. The screen control unit 88may determine the transparency factor of the on-screen keyboard 106 inaccordance with contact duration time, contact pressure, or the likewhen a thumb or a finger of a user, or the like contacts the rear touchpanel 70. For example, the screen control unit 88 may determine thetransparency factor of the on-screen keyboard 106, so that the longer orthe stronger the touch on the rear touch panel 70 is, the higher thetransparency factor of the on-screen keyboard 106 is. This allows a userto view a portion of a screen that is covered by the on-screen keyboard106 when the user inputs characters or the like by using the on-screenkeyboard 106. Therefore, a limited area of the screen can be usedeffectively, and user friendliness can be improved. By adopting a visualexpression where the screen 140 of the application, which has beendisplayed under the on-screen keyboard 106, appears as if it floats if auser touches the rear touch panel 70, a user interface that can beunderstood intuitively can be provided. Alternatively, a user interfacethat can be understood intuitively may be provided by adopting a visualexpression where the on-screen keyboard 106, which has been displayed onthe screen 140 of the application, appears as if it sinks to a levelbelow the screen 140 of the application if a finger or a thumb of a userthat has contacted the rear touch panel 70 detaches from the rear touchpanel 70. Alternatively, whether or not to display an on-screen keyboardmay be switched by tapping the rear touch panel 70 twice quickly.

Upon receiving a flick operation on the rear touch panel 70, theapplication 42 may scroll the screen 140 of the application. If thescreen control unit 88 has not received an operation input on the reartouch panel 70 for a predetermined time period or longer, the screencontrol unit 88 displays the on-screen keyboard 106, which has beendisplayed under the screen 140, again on the screen 140. Consequently,displaying of a screen can be controlled so that the screen 140 of anapplication can be seen only during a period when a user wants to seeit. Therefore, user friendliness can be improved.

FIG. 24 shows a flowchart indicating a procedure of a display controlfunction for an on-screen keyboard screen and an application screen. Ifinput through an on-screen keyboard is required (Y in S402) while anapplication is running (S400), the keyboard display unit 82 displays anon-screen keyboard so that the on-screen keyboard is superimposed on thescreen of the application (S404). Upon receiving an operation input onthe rear touch panel 70 (Y in S406), the screen control unit 88 displaysthe screen of the application on the on-screen keyboard (S408). If anoperation input on the rear touch panel 70 is not received for apredetermined time period or longer (Y in S410), the procedure returnsto the step S404 and the on-screen keyboard, which has been displayedunder the screen of the application, is displayed on the screen of theapplication again. If input through the on-screen keyboard is notperformed (N in S402), the following steps will be skipped. If anoperation input on the rear touch panel 70 is not received in step S406(N in S406), the procedure returns to step S404. If a predetermined timeperiod has not yet passed after the operation input from the rear touchpanel 70 is ceased in step S410 (N in S410), the procedure returns tothe step S408.

Although in the exemplary embodiment described above, a description on adisplay control function for an on-screen keyboard screen and anapplication screen has been given, a control target according to thepresent invention is not limited to an on-screen keyboard screen and anapplication screen. For example, a plurality of on-screen keyboardscorresponding to different types of character set or symbol set (e.g.,an on-screen keyboard screen for entering Japanese and an on-screenkeyboard screen for entering English) may be set as control targets. Inthis case, on-screen keyboards may preferably be scaled down anddisplayed as described in the exemplary embodiment in paragraphs0030-0035. More specifically, a keyboard image that is displayed upperon the display screen may preferably be scaled down and displayed, and akeyboard image that is displayed lower on the display screen maypreferably be displayed in a bigger size than that of the front keyboardimage. The keyboard display unit 82 changes the priorities fordisplaying the plurality of types of on-screen keyboard screens inaccordance with an operation input from the rear touch panel 70. Forexample, each time a touch input is received from the rear touch panel70, the keyboard display unit 82 may shift the priorities for displayingon-screen keyboard screens forward by one, respectively, and may changea priority of displaying an on-screen keyboard that had the highestpriority of displaying to the lowest. In this process, the inputreceiving unit 81 receives a character or a symbol that is selected by auser from among a plurality of characters or symbols displayed on theon-screen keyboard having the highest priority of displaying.Consequently, a plurality of on-screen keyboards can be switched easily.Alternatively, a plurality of application screens may be set as targetsfor controlling according to the present invention.

As described above, the invention disclosed in the exemplary embodimentis characterized by changing the displaying priority, which a candidatescreen image to be displayed has, on the basis of a predeterminedoperation input from a touch panel provided on the rear face of a mobileterminal. As examples of changing the displaying priority, presentedare: changing the front/back on a display screen; changing thetransparency factor; and changing whether or not to display according tothe exemplary embodiment. However, the invention is not limited to theseexamples but any method that changes visual recognition levels of a usercan be adopted.

Given above is an explanation based on the exemplary embodiments. Theseembodiments are intended to be illustrative only and it will be obviousto those skilled in the art that various modifications to constitutingelements and processes could be developed and that such modificationsare also within the scope of the present invention.

What is claimed is:
 1. An input device comprising: a display unitconfigured to display a keyboard screen on a front touch screen thatshows a set of a plurality of characters or symbols that can be input bya user using the front touch screen and receive a user's selection of acharacter or a symbol so as to enter the character or the symbolreceived from the user on a mobile terminal; an input receiving unitconfigured to receive the character or the symbol selected by the userfrom among the plurality of characters or symbols; and a screen controlunit configured to reduce a display priority of displaying the keyboardscreen displayed on the front touch screen if an input operation isreceived from a touch panel provided on a rear face of the mobileterminal, wherein, in case of displaying the keyboard screen whiledisplaying a plurality of screens including a first screen and a secondscreen of an application running in the mobile terminal on the fronttouch screen, the display unit displays the on-screen keyboard so thatthe on-screen keyboard is displayed on top of the first screen and ontop of the second screen, wherein, whenever the input operation isreceived from the touch panel, the screen control unit displays thekeyboard screen under the first screen and on top of the second screen,and wherein, if the screen control unit has not received an additionaloperation input from the touch panel for a predetermined time period orlonger, the screen control unit adjusts the display of the on-screenkeyboard from being displayed under the first screen to being displayedagain on top of the first screen.
 2. The input device according to claim1, wherein the keyboard is shown on top of the first screen and thesecond screen without opacity.
 3. The input device according to claim 1,wherein a double tap to the touch panel provided on the rear face of themobile terminal causes the keyboard to alternately disappear andreappear on the front touch screen.
 4. An input method comprising:displaying a keyboard screen on a front touch panel that shows a set ofa plurality of characters or symbols that can be input on a screen andto receive a user's selection of a character or a symbol so as to enterthe character or the symbol received from the user on a mobile terminal;receiving the character or the symbol selected by the user from amongthe plurality of characters or symbols displayed on the front touchpanel; and reducing a display priority of displaying the keyboard screenif an operation is received from a touch panel provided on a rear faceof the mobile terminal, wherein, in case of displaying the keyboardscreen while displaying a plurality of screens of an applicationincluding a first screen and a second screen, the application running inthe mobile terminal on the front touch screen, the on-screen keyboard sothat the on-screen keyboard is displayed on top of the first screen andon top of the second screen, the keyboard screen is displayed under thefirst screen and on top of the second screen whenever a first inputoperation is received from the touch panel, and wherein, if anadditional operation input has not been received from the touch panelfor a predetermined time period or longer, adjusting the display of theon-screen keyboard from being displayed under the first screen to beingdisplayed again on top of the first screen.